Forgot to cc haskell-cafe. Trying again: ---------- Forwarded message ---------- From: Matthew Gruen <wikigraceno...@gmail.com> Date: Sat, Nov 7, 2009 at 2:16 PM Subject: Re: [Haskell-cafe] Is () a 0-length tuple? To: Pasqualino Titto Assini <tittoass...@gmail.com>
On Sat, Nov 7, 2009 at 2:00 PM, Pasqualino "Titto" Assini <tittoass...@gmail.com> wrote: > The syntax is similar, but what else is? > > In JavaScript there is a "null" value, that is the only value of the null > type. > > Isn't () the same thing? The only value of the unary type? > > Best, > > titto > > Pasqualino "Titto" Assini, Ph.D. > http://quicquid.org/ In JavaScript's case, there is not a null type. The null value belongs to the 'object' type, whereas the undefined value belongs to the 'undefined' type. This is all a lot less useful when you realize that JavaScript has a dynamic type system. But this is JSON, not JavaScript. In JSON, arrays, objects, strings, and numbers can be any number of values. Booleans can be two values. Null can only be one value. Personally, I think a better mapping for () would be JSNull, since both have only one value in normal form. However, there is not necessarily any natural mapping between Haskell values and JSON values. The library tries to provide as many as possible, including (), which it happens to map to JSArray [] instead of JSNull. As long as the library is internally consistent, though, it should be fine. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe